Changes in the heritable attributes of populations of organisms over time. Major mechanisms include drift, natural selection, mutation, and gene flow (migration).

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6
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2answers
147 views

Reasons why living fossils exist?

A living fossil is a living species (or clade) that appears to be similar to another species otherwise known only from fossils, typically with no close living relatives. A living fossil is ...
2
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2answers
189 views

What is the minimum eye?

What is the minimum eye which confers some evolutionary advantage? By minimum I mean anything less than this has no advantage whatsoever and therefore is not favored by natural selection. By eye, I ...
3
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2answers
190 views

What proves that speciation is a pairwise process? [duplicate]

I have been asked this questions by many biology students and even non-biologist without a pretty straightforward answer to give. We are quite accustomed to phylogenetic trees where a common ancestor ...
1
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1answer
51 views

Can life forms exist from simple structures not made of the four bases? [closed]

I understand that all life forms on the planet are made from adenine, gauatine, cytosine and thymine, which chemically joined together to form RNA or DNA (correct me if I'm wrong). This goes on to ...
1
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1answer
41 views

Examples of extant animals in a submature morphologically unstable evolutionary state?

I'm fascinated by evolutionary theory and the predictive aspect of it-the notion of an animal entering a strongly divergent state of evolution whereby it is evolving into a new form yet remains ...
2
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1answer
78 views

Why do Lapidaria margaretae look like stones?

Previous Research I stumbled across a trending reddit post "Lapidaria margaretae looks like stones" (as of 3rd Februrary 2015); but I could not find discussions as to reasons behind why. Question/s ...
29
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3answers
15k views

Why do eukaryotic organisms have introns in their DNA?

We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not ...
5
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3answers
201 views

Why do human ears have a lower boundary for the lowest energy perceivable signal than eyes?

I am currently hearing a lecture about human machine interaction. The lecturer is not a biologist (neither am I, we are both computer scientists), but he makes some statements about biology which I ...
4
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3answers
120 views

Book recommendations for evolutionary models

I was recently working on getting a statistical model of a DNA sequence. To do this I found that understanding evolution quantitatively seems to be quite important. I would really appreciate any book ...
3
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3answers
119 views

How is it possible for the absolute fitness to be more than 1?

The wikipedia definition of Absolute fitness is "the ratio between the number of individuals with that genotype after selection to those before selection. It is calculated for a single generation and ...
1
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0answers
58 views

Baby birds hair and mammal hair is a convergent evolution?

Chicks (baby of chickens) and ducklings seem to have fine hairs, at least something look like hairs to me. Most mammals have hairs, but reptiles, fish, or other animal groups do not have hairs as far ...
0
votes
1answer
158 views

Why have whales and dolphins not evolved to have gills?

It seems at first glance that it would be an evolutionary disadvantage for a sea creature to have to come up to the surface on a regular basis in order to breathe, so why are there animals (e.g. ...
3
votes
1answer
34 views

What is the purpose of narwals' tusks?

I've heard that narwals can grow their tusks up to 16 ft long. What do they need the tusk for? Hunting? Comunication?
3
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1answer
358 views

Pros/cons: linear vs. circular DNA [duplicate]

Why did Eukaryotes evolve to have linear DNA and not circular like Prokaryotes? What are the pros and/or cons?
0
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1answer
49 views

Core architecture of the body encoding [closed]

First of all, I am not a biology guy; I am in Computer Science. But, I have a strong interest in all the mysteries of nature, from universe to human body. So, I want to ask a question related to ...
3
votes
7answers
577 views

Introductory books about evolution

This days I read some debates on evolution. That made me more interested to read something reliable on topic - I mean books. I'm christian - although I think it doesn't matter on that topic - and I ...
3
votes
2answers
362 views

Why are there so many medicinal plants?

Here is wikipedia page containing a list of plants used in herbal medicine. One might first want to argue that many of them actually do not have any medicinal/beneficial effect on heatlth. I think we ...
0
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0answers
18 views

Why didn't animals evolve wheels for locomotion on land? [duplicate]

It seems that our technology heavily favors wheels for the locomotion of machines over land, but evolution came up with legs instead. The following assumptions might be wrong, I'm merely speculating, ...
8
votes
1answer
185 views

Why aren't green eyes more prevalent?

Why aren't green eyes more prevalent, given that the green allele is dominant over the blue one? My understanding is that human eye colour is determined by two genes: 1) HERC2, with alleles Bx, BB ...
4
votes
1answer
70 views

Visualising a subset of the tree of life

I understand that many curated trees of life already exist (eg http://tolweb.org/tree/) but is there any website that allows one to input a list of organisms, and then produce the current best guess ...
4
votes
3answers
138 views

Why are the fertility rates of large predators kept low?

Predators at the top of a food chain, like lions, seem to have a relatively low fertility rate, which fits well to the ecosystem and avoids overpredation. But what is the mechanism that keeps the ...
0
votes
1answer
1k views

Female preference for males who are already in a relationship [closed]

A common saying is that women are generally more attracted towards men who are already in a relationship, and this phenomena does seem to have its own place in popular culture that is not matched by a ...
7
votes
4answers
602 views

If Evolution Is In Progress, Why Fight Extinction?

Natural selection is a central tenet of evolution. However, most biologists seem determined to prevent the extinction of the species that have been selected against. Why is this? Preservation of ...
1
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0answers
30 views

Why does death exist? [duplicate]

The biological purpose of an organism is to reproduce and as soon as reproductive age is passed, aging kicks in and eventually leads to death. (This is what I learned from a gerontologist.) But then, ...
4
votes
1answer
76 views

Why do the proportion of predators increase at mass extinction events?

Why does predation surge with mass extinction? It is caused by extreme selective pressures over resource competition that forces certain species to adapt to predatory niches?
7
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1answer
114 views

What evolutionary advantages are provided by ovoviviparity?

I read that some sharks are ovoviviparous. What advantages and disadvantages are provided by this type of reproduction as opposed to egg laying and live birth?
1
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0answers
109 views

First documented beneficial mutation?

I've been reading up on beneficial mutations, and am curious when we discovered and documented the first one. Can anyone point me to the first documented beneficial mutation? Per request, let me ...
9
votes
3answers
258 views

Why did humans become bipedal?

Somewhere in evolutionary history homo started walking upright and became bipedal. You hear these hypotheses that, by walking upright, they could see better across the grassy savannas to escape ...
2
votes
2answers
146 views

Agony, Hydrophobia and viruses in the light of evolutionary principles

I'm undergraduate physics student, but I've always been interested in biology. So I have a couple of questions about an application of the evolutionary principles to practice. Agony as the last ...
1
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0answers
35 views

Do Parasaurolophus have hands with fingers to grab?

http://en.wikipedia.org/wiki/Parasaurolophus#mediaviewer/File:Parasaurolophus_cyrtocristatus.jpg I cannot tell if the hands have fingers strung together to form a hove, or fingers to grab. I have ...
3
votes
0answers
70 views

Up to date, extensive documentary about dinosaurs?

I just finished reading the Wikipedia page about dinosaurs, and I very much enjoyed it. I knew that much of what I learned in the 80's as a child is (and was) incorrect, and now that I am a parent, I ...
2
votes
0answers
72 views

Why did animals evolve genders? [duplicate]

The majority of animals have two genders, and both are needed in reproduction. It seems like it would be more advantageous for creatures to be hermaphrodites, since they could mate with any member of ...
7
votes
0answers
77 views

How to define “Quasifixation” in continuous approximation of finite population?

Background Many models including the famous very first models derived by Sir Ronald Fisher in his early career, assume infinite population size. In an infinite population, an allele can rise in ...
1
vote
1answer
23 views

Relation between a compound's toxicity and it's concentration level

I know that ammonia is toxic for the body since it disturbs enzymes of mitochondria. I want to know that why the ammonotelic animals don't get affected by it? I mean that even if there is plenty of ...
6
votes
1answer
89 views

Gender and age-specific mutation rate in plants

Background General concept According to Cochran and Harpending (2013), mothers transmits on average a number $x$ of new mutations to their offspring. This number $x$ is independent of the age of the ...
6
votes
5answers
584 views

Relationship Between Evolution and the Increase of Entropy of Earth

I was confronted by this question: Biological evolution of life on Earth, from simple prokaryote-like cells to large, multicellar eukaryotic organisms, A) has occurred in accordance with the laws ...
3
votes
1answer
121 views

Which of the two mitochondorial membranes relate to bacteria according to the endosymbiotic theory?

I seached for endosymbiotic theory in Wiki and I found this about endosymbiotic theory: Symbiogenesis, or endosymbiotic theory, is an evolutionary theory which explains the origin of eukaryotic ...
3
votes
0answers
64 views

Largest direct ancestor of humans

Going back the genealogical lineage from present humans to the beginning of life, what was the biggest - in terms of body size or mass - animal in this sequence? More generally, what would a time vs. ...
1
vote
1answer
61 views

Which came first in hominid evolution: language or bipedalism? [closed]

I suspect both language-use and upright-posture have anatomical consequences. So does the fossil record show which came first? NOTE: To the folks who marked this question "homework": This is ...
0
votes
1answer
89 views

Why do humans have eyebrows? [closed]

Why do humans have eyebrows? It seems that it isn't necessary but only humans have them, correct? So what is the use of them for humans? I hear that they protect our eyes. However, isn't that what ...
2
votes
1answer
408 views

Cell evolution: immortality vs reproduction

Many sci fi movies produce interesting ideas and technologies that we seem to be able to realize in real life at some point. "Lucy" was not one of those movies. But Morgan Freeman's speech in the ...
4
votes
1answer
70 views

Statistics on energy consumption breakdown per biological functions across organisms?

Are there any statistics available on how much energy organisms use for each biological functions (i.e. something similar to the line of "Bacteria spend X% of energy on information processing, Y% for ...
2
votes
1answer
77 views

Gradualism vs. Punctuationalism

TLDR? Just read the bold bits! I started with Darwin's Origin of Species, and then read Dawkins's first three books The Selfish Gene, The Extended Phenotype, and The Blind watchmaker (I just started ...
7
votes
1answer
290 views

Evolutionary reasons why you cannot tickle yourself but masturbate

There are obviously good reasons that explain why you cannot tickle yourself (see e.g. here). This got me thinking why it is possible to masturbate... Wouldn't it make more sense to not being able to ...
8
votes
1answer
145 views

Model for fluctuating selection

Is there any mathematical model to predict the behaviour and long-term consequence of counter-acting selection at different time scale? For example, let's consider the bi-allelic gene A, with alleles ...
4
votes
0answers
48 views

What were the first neural systems like?

I'm curious about the origin of the neural network. I'm thinking perhaps once life evolved beyond the single cell organism, it needed a simple neural network to coordinate those cells, and cell ...
3
votes
1answer
65 views

Mutation Rate in Multicellular Eukaryotes

I always hear people saying that the mutation rate is around $10^{-6}$ or $10^{-7}$. I don't even know if this number is the mutation rate of genes or of a single nucleotides and I actually (almost) ...
1
vote
2answers
98 views

What does to “evolve” exactly mean? [closed]

In this article, the author says: Evolution isn’t “leading up” to anything, it just drunkenly limps along using the same set of tricks in slightly different orders. On other occasions, however, ...
2
votes
0answers
183 views

Mutation-Selection-Drift Equilibrium

mutation-selection-drift equilibrium is one of the most important concept of population genetics. I could easily find the calculations for mutation-secltion equilibrium and for mutation-drift ...
4
votes
1answer
169 views

Why isn't Rh disease present in other mammals?

I have read about Rhesus D Hemolytic Disease of the Newborn, sometimes called "Rh disease". It's rare, but it can happen when an Rh+ baby is conceived by an Rh- mother. This raises many questions. I ...